In a conventional sluice valve for operations, a valve element capable of moving in the orthogonal direction in relation to the pipe axial center of the connection pipe, and valve operation means for movably operating the valve element between open and closed valve positions are provided to a valve case, which is provided with a coupling tube part capable of being externally mounted on a coupling flange of the connecting pipe from the pipe axial center direction; and pulling and securing means for pulling and securing the valve case to the coupling flange is disposed on the coupling tube part of the valve case.
The pulling and securing means comprises threading bolts in a plurality of locations in the circumferential direction of the coupling tube part of the valve case, the bolts being provided with a conical pressing surface that can engage with the external peripheral edge of the back surface side of the coupling flange from the outer side in the radial direction of the pipe.
The coupling part of the fluid device mounted through the flow channel inside the valve case of the sluice valve for operations is joined with the coupling flange of the connecting pipe, and the coupling part of the fluid device and the coupling flange of the connecting pipe are secured and coupled when the plurality of bolts, which is an example of a fastener, are threadably operated through the opening of the coupling tube part of the valve case.